Two Types of Mold Problems

1. Mold where you can see it...

Visible mold- This is typically the fuzzy moss like growth people find on drywall, wood trim, and wood faming or light mold growth on shows in the closest. It is pretty easy to recognize, a little tough to clean up, and most important- difficult to understand how it got there in the first place. Regardless of color and smell, (sometimes a must odor) mold can be dangerous. You should take caution and contact a professional who can help you decipher what is happening to cause visible mold growth in your home. If you think you have mold growing in your home and you can see it, you are probably right. Once it has grown large enough to be recognized visibly, a much more serious moisture issue exists somewhere in the building envelope. The solutions necessary to properly correct this type of mold will ALWAYS involve identifying the source of the problem- a leak, condensation, or high relative humidity at the surface the mold is growing on. 

2. Mold where you can't see it

Invisible mold- Mold can be present in a home even when no visible growth signs are found, like the typical dark wet areas (basements and crawl spaces). In fact, mold is present long before it "grows" big enough to be seen by the naked eye. The invisible parts of the mold fungi are carried through the air like tiny dandelion seeds, landing on the surface of many potential food sources. The truth about mold's presence is a little surprising. It is a naturally occurring bio-organism, present throughout every environment we occupy. The invisible mold is actually the microscopic seed of the mold; unless the right conditions arise, we will never see it grow in our homes.

Excerpt from Mold Prevention Science by Clint S. Cooper and Larry Janesky